We have been able to show that the proliferation and differentiation of lens epithelial cells in vitro is radically affected by the nature of the substratum onto which they are seeded. We are proposing delineate which components of the substratum exert regulatory effects on lens cell differentiation and proliferation by systematic variation of cell substrata, and analysis of the effects of substrata on de novo synthesis of the biomatrix. We propose also to produce monoclonal antibodies to lens epithelial cell membrane proteins, for use in the study of 1) the potential for preventing secondary cataracts using cytolytic- antibody conjugates, 2) the exploration of basic problems in the expression of membrane proteins which are specific to the lens epithelium, and 3) the characterization of epithelial cell culture systems for their validity in the study of lens epithelial cell biology. Thirdly, we are proposing to develop monoclonal antibodies to lens fiber cell membranes, to: 1) continue studies on the role of the MIP in lens gap junctions, 2) explore the role of the recently described MP 70 in lens gap junctions, 3) microelectrode inject antibodies to these proteins into living cultured lens cells, and 4) immunocytochemically characterize fiber cell proteins for their involvement in fiber cell membrane domains such as ball-and- socket joints, sutures, capsular attachments, etc. Finally, all monoclonal antibodies which are generated in the course of this proposal will be tested for their cross-reactivity against human lenses. Positive hybridomas will be expanded, characterized, and frozen for subsequent distribution to interested lens investigators.